On March 31, 2007: Adult Swim aired every episode of Perfect Hair Forever in reverse order. The episodes were digitally degraded to look like several generations-old videotapes with grammatically incorrect subtitles in Engrish. At one point, the subtitles shown on screen were actually for an Aqua Teen Hunger Force episode.

On April 1, 2007: Adult Swim had been advertising that it would be airing Aqua Teen Hunger Force Colon Movie Film for Theaters in its entirety on April Fools' Day. Technically, they made good on their promise by showing the first two minutes (which had long been available on the movie's website) full-screen and the entire rest of the film in a very small picture-in-picture window with its sound played over SAP.

2008: Adult Swim aired a night of unfinished sneak peeks of future upcoming shows in place of their typical programing.

2010: Adult Swim re-aired The Room for a second year in a row, with bumps featuring Tommy Wiseau being interviewed on Space Ghost Coast to Coast. Sex scenes remained censored, but the parental rating was raised to TV-MA.

2013: Adult Swim featured images of cats throughout much of its programming. All of the bumps contained videos and images of cats, while the episodes of the live action shows aired that night had cat faces covering up the faces of the actors. The [adult swim] logo was replaced with "[meow meow]".

2014: Adult Swim premiered an eighth episode of Perfect Hair Forever, seven years following the series finale. This was followed by an unannounced Space Ghost Coast to Coast marathon featuring creator-chosen episodes (including the full version of "Fire Ant", which has rarely been shown on TV). During the marathon, bumps were included between episodes showing outtakes and commentary from the writers and staff. The entire stunt was replayed all day the following day without advertisements on the network's live feed webcam.

2015: Adult Swim aired a marathon of Aqua Teen Hunger Force, featuring a version of the "Coin Hunt" game from Adult Swim's online Fish Center program.

2016: advertisements were shown for the April Fools broadcast, recapping their 12-year history of pranks and hyping up that year's prank. When midnight did occur, regular programming played, with the implication being that the prank for 2016 was that there was no prank.

March 31, 2017: all of the regularly scheduled episodes were aired, but this time, the voice switching gimmick was used in which the proper voices for those shows were replaced with alternate speaking voices, laugh tracks, robotic voices, and other voices along with various sound effects.

April 1, 2017: in another rare two joke-fer, the evening portion of Adult Swim was replaced with the first episode of RRick and Morty's third season unannounced, the first Season 3 episode "The Rickshank Redemption" aired repeatedly until midnight